1. Field of the Invention
The present invention relates to a system for binding a boot on a gliding board, and more particularly a system to fix the rear end of the boot on the gliding board, for which the gliding board can be a ski or a snowboard.
2. Description of Background and Relevant Information
Various types of rear bindings for a boot on a ski, such as rear pivots, on the one hand, and heel-pieces, on the other hand, are known from specialized publications as well as commercially available products.
The rear pivots generally have a circular plate journalled along a vertical axis with respect to the plane of the ski, which receives an elastic release system itself journalled on the plate along a horizontal axis with respect to the plane of the ski due to lateral arms that connect the release system to the ski. One of the drawbacks of this type of binding is that, in the constructive versions mentioned in the French Patents No. 2368973, No. 2299883, and No. 2502019, there is a freedom of rotation of the release system about the vertical axis of the plate that does not favor the reinsertion of the binding. In the constructive version disclosed in the French Patent No. 2598934 which improves the conditions for reinsertion of the aforementioned bindings, there remains a drawback that this type of binding does not make it possible to absorb the forces generated by the bending of the ski. It has been noted that for the bindings described in these patents, some of the release values required by the safety standards are achieved with much difficulty, because these constructions do not make it possible to satisfactorily take into account the return forces due to the bending of the ski when the latter is taking point supports at the tip and tail.
Although heel-pieces, which are the most widely spread rear bindings, offer much interest in terms of comfort of use and safety (insertion, removal, adjustments), they however have a drawback related to skiing that lies in the fact that this type of binding must overcome the disadvantages due to its constructive mode by annexing a return device in order to take into account the return forces generated precisely by the bending of the ski when it is taking point supports at the tip and tail.
The positioning of this return device on a heel-piece then requires particular arrangements thereof, which somewhat complicate its construction and increase its manufacturing cost.
One of the objects of the invention is to propose a binding that is easy to insert and remove, but that does not require the addition of a particular mechanism to absorb the bendings of the ski when they generate variations in length between the abutment and the rear binding.
The device thus proposed by the invention aims at preserving the freedom of the ski at best due to more improved arrangements than those known from the prior pivots while conserving the qualities acknowledged in the heel-pieces.
Another object of the invention is to propose a binding in which the elastic release system comprises new structural arrangements that include only one elastic device ensuring both release and return functions, without requiring auxiliary elastic means as in the heel-pieces.
To this end, the safety binding of a boot on the ski according to the invention includes a body that is movable in a vertical and longitudinal plane with respect to the ski and comprises a jaw adapted to retain an end of the boot, this body being connected to the ski by two curved side arms by means of a first journal axis transverse to the ski, located at the end of the upper arm portion oriented toward the top of said curved arms, and of a second journal axis transverse to the ski affixed to the latter and cooperating, in the vicinity of the end of the boot beneath the level of the sole, with the end of the lower arm portion of the curved arms. Elastic means are housed in the body, adapted to return the jaw toward the ski, wherein the connection of the jaw body with the two curved side arms is constituted, for example, by the cooperation of a guiding pivot affixed to each of the curved side arms with a guiding ramp arranged on each of the lateral walls of the jaw body, wherein the guiding pivot also constitutes the journal axis of a maneuvering lever that can pivot in the zone of the upper end of the curved side arms, whereas the elastic energy means are arranged beneath the journal axis of the maneuvering lever, one of the ends of which is connected to the body of the jaw by another journalled axis, and wherein the lateral walls of the jaw body comprise a second ramp, a so-called xe2x80x9crelease ramp,xe2x80x9d in which cooperates a lug affixed to the curved side arms, located beneath the axis of the guiding pivots and enabling a release of the jaw body in the median vertical plane of the ski, when the user exerts an action on the other end of the maneuvering lever.
According to another embodiment of the binding according to the invention, the guiding ramp of the jaw body is inclined along a direction oriented from the front toward the rear and upwardly with respect to the plane of the ski when the jaw is in the inserted position. This particularly advantageous constructional arrangement makes it possible to absorb variations in length between the front abutment and the rear binding. Indeed, the displacement of the jaw body on the guiding pivots, due to the inclination of the guiding ramp, allows a substantial variation in the free spacing left for different boot sole lengths, but also when the bending of the ski tends to reduce this spacing on the boot during skiing.
According to another characteristic of the invention, the release ramp is constituted of a first portion whose general axis is arranged substantially parallel to the guiding ramp, and of a second portion forming a bend with the first portion, which bend constitutes the zone defining the release point of the jaw.
Finally, according to another alternative embodiment, the technical characteristics of the rear binding according to the invention can be improved due to a particular arrangement of the curved side arms, the surface of the lower arm portions of which, located across from the upper surface of the ski, comprises a profile diverging from the front toward the rear with respect to the surface of the ski extending over at least a portion of the length of the lower arm portions.